Clapper counterweight

ABSTRACT

An electromagnetic counting device having a rotary counter, an electromagnet with a U-shaped core and a coil encircling one of the legs of the core, a one-piece pivotal armature mounted aside the ends of the core legs and functioning as a clapper for the electromagnet and a verge for indexing the counter in stepwise fashion upon momentary energization of the electromagnet, and an inertial member rotatable on the counter shaft and having a radial arm with a bifurcated end receiving an edge of the clapper which provides for rotating the inertial member back and forth in conjunction with the pivotal movement of the clapper.

United States Patent [72] lnventor Ernest G. Hoffman lhmden, Conn. [21] Appl. No. 826,395 [22] Filed May 21, 1969 [45] Patented Nov. 9, 1971 [73] Assignee Veeder Industries inc.

Hartford, Conn.

[54] CLAPPER COUNTERWEIGHT 7 Claims, 3 Drawing Figs.

[52] US. Cl. 235/92 C, 235/92 R, 235/1 C, 340/379 [51] Int. Cl 606m 1/10, 606m 3/12 [50] Field ofScarch 235/131, 1.3, 95.3, 92; 74/575, 589

[56] References Cited UNITED STATES PATENTS 2,673,685 3/1954 Hoffmann 235/92 1/1903 Dixon Primary Examiner-Maynard R. Wilbur Assistant Examiner-Robert F. Gnuse Attorney-Prutzman, Hayes, Kalb and Chilton ABSTRACT: An electromagnetic counting device having a rotary counter, an electromagnet with a U-shaped core and a coil encircling one of the legs of the core, a one-piece pivotal armature mounted aside the ends of the core legs and functioning as a clapper for the electromagnet and a verge for indexing the counter in stepwise fashion upon momentary energization of the electromagnet, and an inertial member rotatable on the counter shaft and having a radial arm with a bifurcated end receiving an edge of the clapper which provides for rotating the inertial member back and forth in conjunction with the pivotal movement of the clapper.

PATENTEDNBV IN VENTOR. ERNEST G. HOFFMAN BYWWM ATTORNEYS CLAPPER COUNTERWEIGHT BRIEF SUMMARY OF THE INVENTION The present invention relates to electromagnetic counting mechanisms of the type comprising a counter and an electromagnetic operator having an electromagnet and a pivotal clapper operable for indexing the counter in stepwise fashion by momentary energization of the electromagnet.

It is a principal aim of the present invention to provide a new and improved electromagnetic counting device of the type described which provides improved counting reliability through the avoidance of miscounts or overcounts due to a fluctuating electromagnetic field or to vibration or other shock forces.

It is another aim of the present invention to provide a new and improved electromagnetic counting mechanism of the type described having improved reliability with AC operation.

It is a further aim of the present invention to provide an electromagnetic counting mechanism of the type described having a new and improved inertial system for inertially improving the pivotal operation of the clapper.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A betterunderstanding of the invention will be obtained from the following detailed description and the accompanying drawing of an illustrative application of the invention.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing in detail, an electromagnetic counting mechanism 8 shown in FIG. 1 is generally of the type described in detail in the copending US. Pat. application Ser. No. 813,490 of L. J. LaPointe et al. filed Apr. 4, 1969, assigned to the assignee of the present application and entitled Electromagnetic Counting Mechanism." Briefly the electromagnetic counting mechanism 8 comprises a plastic frame 10 and an electromagnetic operator 12 and rotary counter 14 mounted on the frame. The electromagnetic operator has a one-piece U-shaped magnetic core plate 16 with generally parallel legs 18, 20, a coil 22 encircling the leg 18, a one-piece pivotal magnetic armature 24 (having a clapper 25 and an integral yoke or verge 26) and an armature return spring 27 extending between the armature and frame. The armature 24 is pivotally mounted on a rib 30 of the frame 10 and with the pivot end 31 of the armature 24 in engagement with the end of the core leg to minimize the air gap loss between the armature and the core leg 20. The armature is mounted aside and extends in overlapping relationship with the ends of the core legs 20, 18 and is biased away from the leg 18 to its normal position shown in FIG. 1 by the return spring 27. When the coil 22 is energized, the armature 24 is pivotally attracted by the electromagnet whereupon a point 34 of the verge 26 engages a plastic star wheel 38 on the lowest order counter wheel 39 (also made of plastic) to index the counter wheel one-half count. Thereafter when the coil is deenergized the spring 27 returns the armature to its normal position and the opposite point 40 of the verge 26 engages the star wheel 38 to index the counter wheel the remaining one-half count. For improving the actuation and release of the clapper by the electromagnet, a shading ring 36 is mounted on the core leg 18 for which purpose the outer end of the core leg 18 is slotted to receive the shading ring.

In accordance with the present invention a rotatable inertial member 41 is rotatably mounted on the counter wheel shaft 42 for inertially controlling the pivotal motion of the armature 24. The shown inertial member 41 comprises a very light molded plastic lever 44 having an opening receiving the shaft 42 and a first long" radial arm 46 with a bifurcated end 48 loosely receiving an end 50 of the clapper 25. The lever 44 has a second short" arm 52 extending generally diametrically opposite (approximately the "long arm 46 and formed with an outer transverse support 54 having opposed pockets 56 for receiving an elongated steel counterweight 58 (of square cross section) which in the shown embodiment weighs approximately 1 gram. The counterweight 58 has an elongated face thereof in engagement with a flat outer face 60 of the transverse support 54 and has recessed ends 62 receiving upstanding side tangs 64 of the pockets 56. Also the pockets are formed with end tangs 66 which may be flexed outwardly for inserting the counterweight 58 on the support 54 and which have inner lips 68 for securely retaining the counterweight in place on the support 54 and within the pockets 56.

The inertial member 41 is adapted to control the motion of the armature in several important ways for improving the reliability and service life of the counting mechanism. As a result of the positioning of the counterweight 58 relative to the ar mature 24 (i.e., such that the center of gravity 70 of the rotatable inertial member 41 as well as the center of gravity 72 of the counterweight 58 are located on the opposite side of their axis of rotation from the pivotal axis of the armature 24 and such that the center of gravity 74 of the pivotal armature remains close to the plane of such axes) any vibration or other shock forces on the mechanism will not cause sufiicient pivotal actuation of the armature 24 to index the counter and in effect any shock caused torque on the armature 24 alone would be substantially offset by the shock caused torque on the inertial member 41.

The inertial member 41 also provides for assuring relatively even motion (including relatively even acceleration and deceleration) of the annature even with a fluctuating electromagnetic field due for example to AC operation of the electromagnet. Accordingly, the armature will not move erratically during AC operation to miscount or to generate an overcount.

Further it has been found that the service life of the counter and the maximum counter speed are increased substantially by the use of the inertial member 41. It is believed that such benefits are due, at least in part, to the more even armature movement and to the more even engagement of the verge 26 with the star wheel 38.

Therefore, in accordance with the present invention the inertial member 41 provides for controlling the motion of the armature to prevent overcounting or miscounting from vibration or other shock or from a fluctuating magnetic field due for example to AC operation, and for additionally substantially increasing the service life of the counter and the maximum counter speed.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

Iclaim:

1. In an electromagnetic counting device having a counter and an electromagnetic operator adapted for indexing the counter comprising an electromagnet, a clapper adapted to be pivoted from a withdrawn for pivotally retracting the clapper to its withdrawn position upon deenergization of the elec' troma'gnet, and indexing means operable by the clapper for indexing the counter in stepwise fashion upon pivotal movement of the clapper, the improvement wherein the electromagnetic operator comprises a rotatable inertial member connected to be rotated in opposite angular directions by the clapper in conjunction with the clapper movement in opposite pivotal directions for inertiaily controlling the pivotal motion of the clapper for improving the operation of the counter, the inertial member and clapper having an interfitting connection to provide for rotating the inertial member in opposite angular directions in conjunction with the clapper movement in opposite pivotal directions.

2. In the electromagnetic counting device of claim ll wherein the center of gravity of the inertial member is on the opposite side of its axis of rotation from the pivotal axis of the clapper.

3. In the electromagnetic counting device of claim 1 wherein the inertial member comprises a rotatable lever connected to the clapper and a counterweight mounted on the lever on the opposite side of the axis of rotation of the inertial member from the pivotal axis of the clapper.

4. The electromagnetic counting device of claim 1 wherein the counter comprises at least one rotatable counter wheel and wherein the inertial member is rotatable coaxially with the counter wheel.

5. In the electromagnetic counting device of claim 1 wherein the counter comprises at least one rotatable counter wheel and wherein the indexing means of the electromagnetic operator comprises a star wheel on the counter wheel and a verge integral with the clapper for pivotal movement therewith, and wherein the center of gravity of the combined verge and clapper is approximately in the plane of the axes of the clapper and inertial member.

6. In an electromagnetic counting device having a counter and an electromagnetic operator adapted for indexing the counter comprising an electromagnet, a clapper adapted to be pivoted from a withdrawn position to an extended position by energization of the electromagnet, spring means position to an extended position by energization of the electromagnet, spring means for pivotally retracting the clapper to its withdrawn position upon deenergization of the electromagnet, and indexing means operable by the clapper for indexing the counter in stepwise fashion upon pivotal movement of the clapper, the improvement wherein the electromagnetic operator comprises a rotatable inertial member connected to be rotated in opposite angular directions by the clapper in conjunction with the clapper movement in opposite pivotal directions for inertially controlling the pivotal motion of the clapper for improving the operation of the counter, the centers of gravity of the inertial member and clapper being related to their respective axes to inertially bias the clapper in opposite pivotal directions as a result of shock on the counting device normal to the common plane of said centers of gravity.

7. in the electromagnetic counting device of claim 6 wherein the inertial member has an arm with a bifurcated end receiving an edge of the clapper. 

1. In an electromagnetic counting device having a counter and an electromagnetic operator adapted for indexing the counter comprising an electromagnet, a clapper adapted to be pivoted from a withdrawn position to an extended position by energization of the electromagnet, spring means for pivotally retracting the clapper to its withdrawn position upon de-energization of the electromagnet, and indexing means operable by the clapper for indexing the counter in stepwise fashion upon pivotal movement of the clapper, the improvemnt wherein the electromagnetic operator comprises a rotatable inertial member connected to be rotated in opposite angular directions by the clapper in conjunction with the clapper movement in opposite pivotal directions for inertially controlling the pivotal motion of the clapper for improving the operation of the counter, the centers of gravity of the inertial member and clapper being related to their respective axes to inertially bias the clapper in opposite pivotal directions as a result of shock on the counting device normal to the common plane of said centers of gravity.
 2. In the electromagnetic counting device of claim 1 wherein the center of gravity of the inertial member is on the opposite side of its axis of rotation from the pivotal axis of the clapper.
 3. In the electromagnetic counting device of claim 1 wherein the inertial member comprises a rotatable lever connected to the clapper and a counterweight mounted on the lever on the opposite side of the axis of rotation of the inertial member from the pivotal axis of the clapper.
 4. The electromagnetic counting device of claim 1 wherein the counter comprises at least one rotatable counter wheel and wherein the inertial member is rotatable coaxially with the counter wheel.
 5. In the electromagnetic counting device of claim 1 wherein the counter comprises at least one rotatable counter wheel and wherein the indexing means of the electromagnetic operator comprises a star wheel on the counter wheel and a verge integral with the clapper for pivotal movement therewith, and wherein the center of gravity of the combined verge and clapper is approximately in the plane of the axes of the clapper and inertial member.
 6. In an electromagnetic counting device having a counter and an electromagnetic operator adapted for indexing the counter comprising an electromagnet, a clapper adapted to be pivoted from a withdrawn position to an extended position by energization of the electromagnet, spring means for pivotally retracting the clapper to its withdrawn position upon de-energization of the electromagnet, and indexing means operable by the clapper for indexing the counter in stepwise fashion upon pivotal movement of the clapper, the improvement wherein the electromagnetic operator comprises a rotatable inertial member connected to be rotated in opposite angular directions by the clapper in conjunction with the clapper movement in opposite pivotal directions for inertially controlling the pivotal motion of the clapper for improving the operation of the counter, the inertial member and clapper having an interfitting connection to provide for rotating the inertial member in opposite angular directions in conjunction with the clapper movement in opposite pivotal directions.
 7. In the electromagnetic counting device of claim 6 wherein the inertial member has an arm with a bifurcated end receiving an edge of the clapper. 